Recently, there has been an increasing interest in energy storage technology. Electrochemical devices have been widely used as energy sources in the fields of cellular phones, camcorders, notebook computers, PCs and electric cars, resulting in intensive research and development into them.
In this regard, electrochemical devices are one of the subjects of great interest. Particularly, development of rechargeable secondary batteries has been the focus of attention. Recently, research and development of such batteries are focused on the designs of new electrodes and batteries to improve capacity density and specific energy.
Many secondary batteries are currently available. Among these, lithium secondary batteries developed in the early 1990's have drawn particular attention due to their advantages of higher operating voltages and much higher energy densities than conventional aqueous electrolyte-based batteries, for example, Ni-MH, Ni—Cd, and H2SO4—Pb batteries.
Meanwhile, electrochemical devices which are mounted as a power supply in electrically powered tools should have good resistance to vibration taking use environment into account. The electrode taps of the electrochemical devices may be damaged by external force due to vibration generated when using the electrically powered tools, and a short circuit between the cathode tap and the anode tap may occur.
Therefore, there is a need for developing an electrochemical device having improved vibration-resistance to be effectively used in electrically powered tools or other equipments.